This invention broadly relates to a new paint stripping molten salt bath composition and method of using same.
The state of the art is indicated by the following U.S. Pat. Nos.: Lang, 1,714,879; Hannah, 2,898,246; Wilson, 3,168,477; Rausch, 3,425,947; Ng, 3,690,949; Shoemaker, 3,790,489; Faler, 3,393,689; Shoemaker, 3,260,619; Faler, 3,174,491; Faler, 3,126,301; Shoemaker, 3,024,139; Shoemaker, 2,967,530; Webster, 2,936,270; Shoemaker, 2,936,278; Webster, 2,847,374; Shoemaker, 2,863,465; Wainer, 3,615,815; Seibert, 3,455,737; Schwartz, 2,939,209; Wainer, 3,000,766; Kemper, 3,770,501; Moore et al., 18,242; O'Reilly, 3,448,509; Pajes, 2,854,360; Sundh, 1,412,978, and U.S. Patent 3,647,358.
Prior formulations for paint stripping salt baths conventionally have been made of molten nitrate/caustic mixtures. However, while these prior formulations generally provided relatively complete combustion of organic compounds they also resulted in the rapid build up of carbonates or solid sludge like materials in the bath, which carbonates and sludge are detrimental to bath operation. If it was attempted to overcome this problem by going to a low nitrate-high caustic salt bath formulation very substantial amounts of tarry or scummy residues were formed in the molten salt bath and this interfered with the paint stripping operation of the bath and it also interfered with the washing of fixtures which had been treated in the bath. Accordingly there has long been desired a salt bath formulation which would provide an essentially complete combustion of the organics or paint material but wherein sludge or carbonate build up would be very small compared with the prior high nitrate formulations, and yet without the problem of the build up of tarry or scummy residues which had occurred when using a low nitrate formulation.
Accordingly one object of the invention is to provide a new and improved paint stripping molten salt composition and method of using same.
Another object of the present invention is to provide a new paint stripping molten salt bath wherein there is obtained essentially complete combustion of organic compounds but without the rapid build up of carbonates or sludge-like material as has occurred in prior salt baths used for paint stripping.
Other objects, features and advantages of the present invention will become apparent from the subsequent description and the appended claims.